Castor



March 10, 1936.

F. A. BRAYLEY 2,@3,5W

CASTER Filed Dec. 24, 1954 Patented Mar. 10, 1936 UNITED STATES PATENT OFFICE 1 Claim.

My present invention relates to casters and more particularly to ball bearing castors.

The principal object of my invention is an improved castor;

Another object is an improved ball bearing castor;

Another object is an improved castor having a bearing surface comprising a single ball;

Still another object is an improved bearing case for a ball bearing castor;

Qther objects and novel features comprising the construction and operation of my improved castor will appear as the description of the same progresses.

Referring to the drawing illustrating my invention;

Fig. 1 is partial elevation and cross-section, the castor unit being in elevation;

Fig. 2 is a typical cross-section taken through the castor unit and the leg of a chair or other piece of furniture;

Fig. 3 is a plan view of the castor shown in Figs. 1 and 2;

Fig. 4 is a cross-section similar to Figs. 1 and 2 showing a modification of the castor casing, and

Fig. 5 is another modification showing a still further modification of the castor casing.

Referring more in detail to the drawing, l indicates the leg of a chair, for instance, the end of which has been recessed at H to receive the castor casing I2 which in Figs. 1 and 2 consists of a cylindrical shell open on the bottom and closed at the back. Over the open end is placed a disc I3 which is provided with spur members 14 disposed at ninety degrees to the disc l3 and adapted to be driven into the chair leg I0.

The disc [3 is the same in all the various views and is attached to the casing l2, [2a or I2b by means of screws l5. The inner central portion of the disc I 3 is recessed and counterbored at Hi to receive a ball H a portion of the periphery of which protrudes through the disc as illustrated in the drawing.

In Figs. 1 and 2 I have provided a screw pin [8 at the back of the casing l2 against which the ball l1 rests and revolves the opening it in the disc I3 acting as a second point of contact.

In Fig. 4 I have provided a back support l9 struck up from the metal comprising the casing l2a. This support and bearing member l9 also acts as a stiffener for the back of the casing l2a. If necessary or desirable I may make the whole back of the casing l2a inwardly converging in a funnel-like manner without piercing through the casing, instead of the central portion as 10 shown in the drawing,

In Fig. 5 I show a modification of the casing as indicated at l2b in which I have provided a cup shaped bearing surface 20.

In all the figures illustrating my invention it will be noted that I have provided a two point contact, the opening l6 being the same in all cases being a ring surface around the ball 11. In Fig. 5 the second point is the cup surface which is identically the same as the ball periphery 20 and extends half around the ball H. In all other cases the second point contact is directly at the back of the ball ll either by means of the pin H3 or the cone point l9.

Having thus described my invention what I claim as new is:

An improved castor comprising in combination,

a cylindrical casing open at one end and closed at the other end, the said closed end comprising a depressed central portion the side walls of which are conically shaped, said conically shaped walls being depressed from the horizontal closed end of the casing, a concaved bearing surface located on the inside apex portion of said depressed central portion, a cover disc located on the open end of said cylindrical casing and having a central opening concaved on the inner side, means for attaching said disc to said casing, spurs located on the outer periphery of said disc and parallely disposed to the side walls of said casing, a ball seated against the concaved bearing surface of said depressed portion and engaging with the inner concaved surface of the central opening of said disc.

FREDERIC A. BRAYLEY. 

